Utility and industrial plants such as power plants, electricity generation plants, waste-to-energy facilities, cement kilns, and other facilities firing fossil fuels can be subject to strict limits with respect to air emissions and waste water discharge to help ensure clean and environmentally sound operation thereof. Traditionally, compliance with air emissions limits is achieved through the use of a wet or dry flue gas desulfurization system. Water treatment systems can be utilized to treat waste water discharge from desulfurization systems to comply with applicable waste water regulations. Examples of flue gas cleaning systems and/or waste water treatment systems can be appreciated from International Publication No. WO 2006030398, U.S. Patent Application Publication Nos. 2009/0294377, 2011/0262331, 2012/0240761, 2013/0248121, and 2013/0220792, U.S. Pat. Nos. 6,076,369, 7,524,470, 7,625,537, 8,388,917, and 8,475,850, European Patent Publication No. EP 1 955 755, and Japanese Published Patent Application No. JP 2012200721.
The capital costs of air emissions systems utilizing a wet or dry flue gas desulfurization system along with an associated balance of plant systems, e.g., ducts, fans, bulk material handling systems, etc., can often be relatively expensive, e.g., between $200 to $500 per kilowatt (kW). In retrofit situations, capital costs associated with such systems may render a plant uneconomical. In addition to capital costs, wet and dry flue gas desulfurization systems also involve substantial operating costs associated with reagent consumption, auxiliary power usage, operations staffing, as well as management staffing.
Plants' waste water treatment systems can be configured to neutralize and precipitate heavy metals, perform biological treatment of the waste water, and also filter the waste water to clean the water prior to environmental release thereof. Costs associated with waste water treatment systems can be relatively significant in terms of both capital costs and operating costs. Accordingly, lower cost, more efficient waste water treatment systems are needed.